What do the following two equations represent? $-2x+5y = 5$ $-15x-6y = -5$
Solution: Putting the first equation in $y = mx + b$ form gives: $-2x+5y = 5$ $5y = 2x+5$ $y = \dfrac{2}{5}x + 1$ Putting the second equation in $y = mx + b$ form gives: $-15x-6y = -5$ $-6y = 15x-5$ $y = -\dfrac{5}{2}x + \dfrac{5}{6}$ The slopes are negative inverses of each other, so the lines are perpendicular.